branched. Therefore, a technique such as pinching, manual removal of shoot apices, to overcome apical dominance and encourage lateral branching is a commercial recommendation in ornamental plant production ( Meijon et al., 2009 ) including pepper ( Larson
Songul Sever Mutlu and Ece Agan
Hans C. Wien
In previous studies, pinching of nonbranching sunflower cultivars in the seedling stage led to a more than 3-fold increase in stem production ( Wien, 2016 ). Many sunflower cultivars developed for cut flower use produce more than one stem, and are
Hans C. Wien
The practice of removing an herbaceous plant’s growing point (commonly termed pinching or topping) has been used for many centuries to affect growth, plant productivity, or shape ( Escher, 1996 ; Hunt, 1893 ). Most commonly, pinching is used to
Amir Rezazadeh, Richard L. Harkess, and Guihong Bi
and well-shaped, symmetrical plants. To achieve better uniformity, growers often use cultural practices including hand pinching and PGRs to release apical dominance. This allows dormant, lateral buds to grow resulting in well-branched plants ( Grossman
Amir Rezazadeh and Richard L. Harkess
is necessary to provide desirable marketable products. Numerous techniques have been used to control height and produce marketable plants. Pinching is the removal of the apical bud to overcome apical dominance and promote lateral branch development
Janet C. Cole, Robert O. Brown, and Mark E. Payton
uniconazole, or pinching reduces plant growth of oakleaf hydrangea. Materials and methods 2002 Greenhouse study. Uniform rooted cuttings, about 30 cm in height, of ‘Alice’ oakleaf hydrangea were planted in 1-gal containers on 26 Sept. in Stillwater, OK. The
Terri Woods Starman
Manually pinched plants of 18 cultivars of Impatiens hybrids (Keintzler New Guinea impatiens) were compared to control plants to determine the effect of apical meristem removal on flowering, growth and branching. Pinching delayed days to anthesis (first flower) of all cultivars, however, further delay in days to marketability (5 flowers open) was dependent upon cultivar. Plant area and fresh and dry weight were not affected by pinching plants of any cultivar. Cultivar influenced response to pinching treatments for plant height and plant width. Secondary branch number was increased by approximately 3 branches for all cultivars when plants were pinched. There were interactions between cultivar and treatment for primary, tertiary, and total branch number. Measured improvements in plant form determined two cultivars, Sylvine and Thecla, should be pinched. Chemically pinching these two cultivars with dikegulac at 780 mg·liter-1 was comparable to manually pinching plants.
James M. Rawson and Richard L. Harkess
Lagerstroemia has potential for development as a potted florist crop for early spring sales. The number and timing of pinching or number of liners per container were examined as a means of developing a more compact plant that is in proportion to the container. On 20 July 1996, either one or three rooted liners of Lagerstroemia `Victor' or `Zuni' were planted into 1500-ml (15 cm in diameter) containers in a pine bark: peat moss (3:1 v/v) substrate amended with 6 kg·m–3 MicroMax plus (Scotts Company, Inc., Marysville, Ohio). The plants were topdressed with 10 g SierraBlen 17–6–12 (Scotts Company, Inc., Marysville, Ohio) slow-release fertilizer. The liners received 0, 1, 2, 3, or 4 pinches and were pinched in a complete factorial 0, 2, 4, and 6 weeks after potting. There were 32 pinching treatments with 5 replications. The plants were grown outside until 30 Sept. 1996, when they were moved into a greenhouse. Plant height, width, and a visual rating were collected 13 Nov. 1996. There was no significant difference in plant size or visual rating of `Victor' regardless of the number or timing of pinches or of the number of liners per pot. `Zuni' had significantly the best visual ratings and largest size when grown with three liners but the timing and number of pinches had no significant effect. `Victor' is a dwarf cultivar growing to only 1 m in the landscape while `Zuni' is a semi-dwarf, growing to 2.7 m.
David A. Gilbertz
Spray applications of 15 or 30 mg uniconazole or 30 or 60 mg paclobutrazol/liter (20 ml/1.5-liter pot) were sprayed 0, 2, or 4 weeks after pinching of Dendranthema × grandiflorum (Ramat.) Kitamura `Bright Golden Anne' plants. Plants were shorter the earlier growth regulators were applied. Plants were more responsive to uniconazole, requiring paclobutrazol at up to four times the uniconazole concentration to achieve the same height control. Time to flowering was also lengthened the earlier applications were made, up to 3 days compared to nontreated plants. Flower diameter was only minimally affected by the treatments. Chemical names used (2RS,3RS)-1-(4-chlorophenyl)-2-1,1-dimethylethyl)-(1H-1,2,4-triazol-1-yl)pentan-3-ol(-paclobutrazol);(E)-l(p-chlorophenyl) -4,4-dimethyl-2-(1,2,4-triazol-1-yl-1-penten-3-ol) (uniconazole).
James M. Garner, Starla A. Jones, and Allan M. Armitage
Two studies were conducted to determine the influence of decapitation (pinch treatment) and photoperiod treatments on stem length, days from planting to harvest, and flowering stem yield in two delphinium cultivars. Plants of Delphinium ×belladonna Hort. ex Bergmans `Völkerfrieden' received a hard pinch (removal of apex and all stem and leaf tissue associated with leaves ≤10 cm), soft pinch (removal of apex and all stem and leaf tissue associated with leaves ≤4 cm), or no pinch. Plants of the D. elatum L. `Barbara' series were grown under either long- or short-day photoperiod, each treatment with or without receiving a soft-pinch. Time from planting to harvest was longer in pinched plants than in nonpinched plants of both cultivars regardless of photoperiod. Flowering stems were longer in hard- and soft-pinched plants of `Völkerfrieden' compared to nonpinched plants, and with `Barbara', stem length of pinched plants was either longer or similar to that of nonpinched plants regardless of photoperiod. At 30 days after the commencement of harvest, yield of flowering stems for hard-pinched plants of `Völkerfrieden' was higher than that for nonpinched plants, but yield from soft-pinched plants was similar to that for those not pinched. Stem yield for `Barbara' was higher for pinched plants under the long-day photoperiod, but under short days, yield from pinched plants was similar to that for those not pinched. Long days appear to increase yield and reduce production time in delphinium cultivars. Commercial benefits may be realized by growing nonpinched plants for earliness and pinched plants for longer stems and higher yield.